decode-greyscale-alpha ( loading-image -- byte-array )

Vocabulary

images.png

Inputs

loading-image

an object

Outputs

byte-array

an object

Definition

USING: accessors arrays grouping kernel sequences ;

IN: images.png

: decode-greyscale-alpha ( loading-image -- byte-array )
    [ uncompress-bytes ] [ bit-depth>> ] bi 16 = [
        4 group [ first4 [ swap ] 2dip 4array ] map
        B{ } concat-as
    ] when ;